Apparatus for treating gases

ABSTRACT

A combustion apparatus for thermally treating gases which are difficult to handle by mechanical compressors or pumps. The apparatus comprises an internal combustion burner capable of producing a high-temperature and high-velocity jet stream of gases which is directed into an adjacent coaxially aligned chamber where it entrains, mixes with and propels a low-velocity stream of gases to be treated which enters the chamber through an opening in the enlarged inlet end of the chamber. The resultant gas stream is propelled through a constricting outlet section of the chamber having a cylindrical throat coaxially aligned with the jet stream. The relative location and size of the throat section are established so that the natural dispersion angle of the jet stream intersects the chamber walls adjacent the inlet end of the throat section or between the inlet and outlet ends of the throat section. A treating chamber is provided adjacent the outlet of the throat section.

United States Patent 72] Inventors John D. Nesbitt Toledo; Klaus H. Hemsath, Sylvania, both of Ohio [211 App]. No. 862,249 [22] Filed Sept. 30, 1969 [45] Patented Sept.2l,l97l [73] Assignee Midland-Ross Corporation Toledo, Ohio [54) APPARATUS FOR TREATING CASES 9 Claims, 2 Drawing Figs.

[52] US. Cl 23/277 C, 110/8 A, 431/5, 431/202 [51] Int. Cl F23g 7/06 [50] Field of Search 23/277 C; 48/180; 110/8 A, 18 A; 431/5, 202

[56] References Cited UNlTED STATES PATENTS 2,879,862 3/1959 Burden, Jr 23/277 C 2,992,084 7/1961 Schropp 48/180 3,195,608 7/1965 Voorheis et aL. 431/202 X $237,399 3/1966 Hamblin et al. 23/277 C 3,251,656 5/1966 Edwards Primary ExaminerJoseph Scovronek Assistant ExaminerR. E. Serwin Attorneys-Harold L. Mensing and Peter Vrahotes ABSTRACT: A combustion apparatus for thermally treating gases which are difficult to handle by mechanical compressors or pumps. The apparatus comprises an internal combustion burner capable of producing a high-temperature and highvelocity jet stream of gases which is directed into an adjacent coaxially aligned chamber where it entrains, mixes with and propels a low-velocity stream of gases to be treated which enters the chamber through an opening in the enlarged inlet end of the chamber. The resultant gas stream is propelled through a constricting outlet section of the chamber having a cylindrical throat coaxially aligned with the jet stream. The relative location and size of the throat section are established so that the natural dispersion angle of the jet stream intersects the chamber walls adjacent the inlet end of the throat section or between the inlet and outlet ends of the throat section. A treating chamber is provided adjacent the outlet of the throat section.

APPARATUS FOR TREATING GASES BACKGROUND OF INVENTION This invention pertains to a gas treating apparatus in which a low-velocity gas stream to be treated is caused to flow into a chamber where it is entrained and mixed with a high-velocity jet stream and conveyed thereby directly into a reaction chamber. It is particularly useful in applications in which the gas stream to be treated is such that it is difficult to convey by ordinary mechanical means, for instance by fans or compressors. Examples of gases which are difficult to handle by mechanical means are hot gases, corrosive gases, gases containing gunk, or gases having some combination of these elements.

Although the principles of this invention have utility in the treatment of gases which are difficult to treat by prior art methods, their use is not restricted only to such gases. The kinetic energy in the hot jet stream coupled with the geometry of the entrainment and mixing chamber, especially the throat section thereof, produce a surprisingly efficient mixing and pumping device. Therefore the principles may be used where mixing is the primary function or where both the mixing and pumping capabilities are required.

The principles of this invention have been applied to the incineration of fumes emanating from industrial processes, such as in electrical-wire-coating operations wherein a plastic or rubber-type insulative material is applied to the wire and then thermally set or dried in a furnace. The furnace fumes generated during the process contain solvents and other incompletely oxidized material.

Generally speaking, the invention comprises an internal combustion burner having a combustion chamber which restricts the expansion of the burning fuel-air mixture and produces a pressure buildup within the chamber. The hot products of combustion are released through an orifice or nozzle section and form a high-velocity jet stream which is directed towards a constricting throat section at the opposite end of an adjacent chamber. This latter chamber, to be known as the mixing and entrainment chamber, coaxially surrounds the jet stream and has a base section which is sufficiently large to allow the high-velocity jet stream to act substantially as a jet in free space. An inlet for the gas to be treated is located in this base section as remote as is practically possible from the throat section of the entrainment chamber. The throat section is coaxially aligned with the jet stream and has a cross-sectional shape which is the same as the cross-sectional shape of the approaching jet stream. Preferably the jet stream has a circular cross section and the throat section is cylindrical in form with a length equivalent to its diameter. The diameters of throat section and the burner chamber outlet and the distance between the throat inlet and burner outlet are such that the expanding jet stream completely fills the throat opening, but does not expand beyond the diameter of the throat section more than about percent of its diameter prior to its entrance into the throat section. This arrangement of a free expanding jet entering a relatively short cylindrical throat outlet provides substantially complete mixing of the two gas streams in a distance from the burner outlet which is equivalent to about four throat diameters of the throat section or less. In other words, the mixing of the two gas streams is substantially completed and the resultant gas stream has been raised to the desired reaction temperature when it has reached the outlet of the throat section of the entrainment and mixing chamber. Upon exiting the entrainment and mixing chamber, the resultant gas stream enters an enlarged section of an incineration or reaction chamber where it resides until the desired reaction is completed.

It is a general object of this invention to produce a gas-treating apparatus which utilizes the kinetic energy in a highvelocity jet stream of hot gases to induce a lower velocity lowpressure gas stream to enter a surrounding chamber and become entrained and homogeneously mixed with the jet stream and further uses the heat in the jet stream to incinerate or otherwise thermally treat the other gas stream.

It is another object of this invention to produce a simple, efficient, compact, and durable mixing device for gases which is economical to construct and maintain.

It is still another object of this invention to produce a fume incinerator which is capable of handling hot fumes, corrosive fumes, and fumes containing contaminants which render them difficult to convey by ordinary mechanical means such as by fans and compressors.

The above mentioned objects and other objects and advantages and the manner of attaining them will be apparent from the following detailed description of embodiments of this invention made with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevation view in section of a fume incinerator embodying the principles of this invention adapted for the incineration of fumes containing sufficient oxygen for complete combustion.

FIG. 2 is an elevation of a fume incinerator similar to that of FIG. 1, but adapted for use with fumes having insufficient oxygen for complete combustion.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 and 2 of the drawings respectively show a fume incinerator l0 which is adapted for the incineration of fumes having sufficient oxygen for complete combustion, and a fume incinerator 20 adapted for the incineration of fumes lacking sufficient oxygen for complete combustion. The incinerators l0 and 20 each have a burner 22 or 24 comprising a combustion chamber 26 or 28 and a means 30 or 32 for injecting a mixture of fuel and air into these combustion chambers. The fuel-air injection means 30 in FIG. 1 is of the type generally denoted as a premix type which is primarily designed for operating with a stoichiometric or nearly stoichiometric ratio of fuel and air. The fuel-air injection means 32 in FIG. 2 is generally known as a combustor type which is capable of stable operation with other than a stoichiometric ratio between fuel and air, particularly a substantial excess of air to fuel. Valve means are provided to control the amounts and ratios of fuel and air supplied to the burners so that the temperatures and velocities of the jet streams may be regulated. The preferred configuration of the fuel-air combustion chambers 26 and 28 is shown in FIGS. 1 and 2 respectively. Other configurations may be used as long as the combustion products exiting the burner have a sufficiently high velocity and temperature, for example, between about 600 and 1,000 feet per second and between about 2,800 F. and 3,400 F. Each combustion chamber 26 or 28 has an intermediate section 38 or 40 which is cylindrical in form and has a length in excess of its diameter. The end sections of the combustion chambers converge conically with the included angle of the cone at the fuelair-injecting end being about 90, and the included angle of the cone at outlet end being about 60. The cones are truncated to provide inlet and outlet orifices and the outlet orifice preferably is provided with a short tunnel or nozzle section 42 or 44. Both combustion chambers are made from refractory material. The wall 46 of the conical outlet end of the combustion chamber 26 may be made from an especially dense refractory material to increase its durability as shown in FIG. 1. Also the combustion chamber walls may be surrounded by a layer of insulation 47 and a steel casing 48.

Connected to the burner section and in fluid communication with the outlet thereof is an entrainment and mixing chamber 50 or 52 defined by refractory walls as shown in FIGS. 1 and 2 respectively. The base 54 or 56 of this chamber,

- adjacent the burner outlet, is enlarged sufficiently so that the let in the throat end of the entrainment and mixing chamber. For incineration purposes, the entrainment ratio between the volume of the fume and the volume of the gases of the jet stream at standard temperature and pressure is suitably between about 2.5-l and 7.5-1, and preferably is between about 3-1 and 4-1. The outlet or throat section 62 or 64 is preferably cylindrical in shape and has a length which is approximately equivalent to its diameter. It is coaxially aligned with the jet stream and preferably has a diameter equivalent to about four times the diameter of the burner outlet orifice 42 or 44. The entrance end of the cylindrical throat section may be located a distance equivalent to about to 13 diameters of the burner outlet from the burner outlet. Preferably this distance is about 11.5 diameters. The approach to the throat section is preferably conical in form with an included angle of between about 75 to 85. Using the preferred dimension relationships and other relationships expressed above, the two streams are substantially homogeneously mixed when they reach the outlet of the throat section of the entrainment and mixing chamber.

A reaction chamber 70 or 72 for containing the mixed gases until the incineration or other reaction is completed is provided at the outlet end of the entrainment and mixing chamber 50 or 52. The reaction chamber 72 in FIG. 2 is connected to the entrainment and mixing chamber 52 so that there is an annular gap or fluid passageway therebetween for the admission of air into the reaction chamber under pressure. A plenum housing 74 is sealingly connected to the base of the reaction chamber 72 and around the burner body 24. Air is admitted to the plenum housing through a large conduit 76 having a flowcontrolling damper 78. A means is also provided for uniformly introducing air under pressure into the fume stream prior to its entry into the mixing and entrainment chamber. This means may include a pipe 80 for feeding air to an annular distributor 82 connected between the outlet end of the fume-conveying conduit 84 and the fume inlet 60 of the entrainment and mixing chamber. Accordingly, in the embodiment of FIG. 2 which is adapted for incineration of fume having insufficient oxygen for complete combustion, additions of air may be made at one or more of the following locations: through the burner, into the fume stream prior to its entry into the mixing and entrainment chamber, and also directly into the base of the incineration chamber.

While the invention has been described with reference to preferred embodiments and specific applications, it is to be understood that the inventive principles may be embodied and applied otherwise without departing from the scope of and spirit of this invention.

We claim:

1. A gas-treating apparatus comprising: an internal combustion burner having wall means defining its combustion chamber with an outlet opening for producing a high-velocity jet stream of gases, a second wall means defining an entraining and mixing chamber having an enlarged entrance end in fluid communication with said burner outlet and having a cylindrical outlet opening of reduced size coaxially aligned with said jet stream, inlet means in said entraining and mixing chamber for the influx of a low-velocity gas stream thereinto, and a third wall means defining a reaction chamber adjacent said cylindrical outlet opening in fluid communication therewith.

2. An apparatus according to claim 1 wherein the length of said cylindrical outlet opening is about equivalent to its diameter.

3. An apparatus according to claim 1 wherein the diameter of said cylindrical outlet opening is between about three and five times the diameter of said burner outlet opening.

4. An apparatus according to claim 3 wherein the entrance to said cylindrical outlet is at a distance of between about 10 to 13 times the diameter ofsaid burner outlet opening.

5. A gas-treating apparatus comprising: an internal combustion burner having wall means defining its combustion chamber with an outlet opening for producing a high-velocity jet stream of gases, a second wall means defining an entrainin and mixing c amber having an enlarged entrance end in flul communication with said burner outlet and having a cylindrical outlet opening of reduced size coaxially aligned with said jet stream, the entrance end of said cylindrical outlet opening being located a distance equivalent to between about 10 to 13 times the diameter of said burner outlet from said burner outlet, the diameter and length of said cylindrical outlet opening being equivalent to between about three to five times the diameter of said burner outlet, inlet means in said entraining and mixing chamber for the influx of a low-velocity gas stream thereinto, and a third wall means defining a reaction chamber adjacent said cylindrical outlet opening in fluid communication therewith.

6. An apparatus according to claim 5 wherein the diameter and length of said cylindrical outlet opening is equivalent to about four times the diameter of said burner outlet and the distance from said burner outlet to said entrance end of said cylindrical outlet opening is equivalent to about I 1.5 times the diameter of said burner outlet.

7. A fume incinerator comprising: an internal combustion burner means for producing a jet stream of gases having a velocity between about 600 and 1,000 feet per second and a temperature between about 2,800-3,400 F. emitting from burner outlet, wall means defining an entrainment and mixing chamber having an enlarged entrance end in fluid communication with said burner outlet and having a cylindrical outlet opening of reduced size coaxially aligned with said jet stream, inlet means in said entraining and mixing chamber for the influx of a low pressure low velocity fume stream, and a second wall means defining an incineration chamber adjacent said cylindrical outlet in fluid communication therewith.

8. A fume incinerator according to claim 7 wherein the 1 diameter and length of said cylindrical outlet opening is equivalent to between about three to five times the diameter of the burner outlet opening, and the distance from the entrance end of said cylindrical outlet opening to said burner outlet is equivalent to between about 10 to 13 times the diameter of said burner outlet.

9. A fume incinerator according to claim 8 wherein the diameter and length of said cylindrical outlet opening is equivalent to about four times the diameter of said burner outlet, and the distance from the entrance end of said cylindrical outlet opening to said burner outlet is equivalent to about 1 1.5 times the diameter of said burner outlet. 

2. An apparatus according to claim 1 wherein the length of said cylindrical outlet opening is about equivalent to its diameter.
 3. An apparatus according to claim 1 wherein the diameter of said cylindrical outlet opening is between about three and five times the diameter of said burner outlet opening.
 4. An apparatus according to claim 3 wherein the entrance to said cylindrical outlet is at a distance of between about 10 to 13 times the diameter of said burner outlet opening.
 5. A gas-treating apparatus comprising: an internal combustion burner having wall means defining its combustion chamber with an outlet opening for producing a high-velocity jet stream of gases, a second wall means defining an entraining and mixing chamber having an enlarged entrance end in fluid communication with said burner outlet and having a cylindrical outlet opening of reduced size coaxially aligned with said jet stream, the entrance end of said cylindrical outlet opening being located a distance equivalent to between about 10 to 13 times the diameter of said burner outlet from said burner outlet, the diameter and length of said cylindrical outlet opening being equivalent to between about three to five times the diameter of said burner outlet, inlet means in said entraining and mixing chamber for the influx of a low-velocity gas stream thereinto, and a third wall means defining a reaction chamber adjacent said cylindrical outlet opening in fluid communication therewith.
 6. An apparatus according to claim 5 wherein the diameter and length of said cylindrical outlet opening is equivalent to about four times the diameter of said burner outlet and the distance from said burner outlet to said entrance end of said cylindrical outlet opening is equivalent to about 11.5 times the diameter of said burner outlet.
 7. A fume incinerator comprising: an internal combustion burner means for producing a jet stream of gases having a velocity between about 600 and 1,000 feet per second and a temperature between about 2,800* -3,400* F. emitting from burner outlet, wall means defining an entrainment and mixing chamber having an enlarged entrance end in fluid communication with said burner outlet and having a cylindrical outlet opening of reduced size coaxially aligned with said jet stream, inlet means in said entraining and mixing chamber for the influx of a low pressure low velocity fume stream, and a second wall means deFining an incineration chamber adjacent said cylindrical outlet in fluid communication therewith.
 8. A fume incinerator according to claim 7 wherein the diameter and length of said cylindrical outlet opening is equivalent to between about three to five times the diameter of the burner outlet opening, and the distance from the entrance end of said cylindrical outlet opening to said burner outlet is equivalent to between about 10 to 13 times the diameter of said burner outlet.
 9. A fume incinerator according to claim 8 wherein the diameter and length of said cylindrical outlet opening is equivalent to about four times the diameter of said burner outlet, and the distance from the entrance end of said cylindrical outlet opening to said burner outlet is equivalent to about 11.5 times the diameter of said burner outlet. 